Question

1. Define a class named Book that contains:
 An int data field named pages that stores the number of pages in the book.
 A String data field named title that represents the title of the book.
 A constructor with parameters for initializing pages and title.
 The getter and setter methods for all data fields.
 A toString method that returns book information, including the book title and pages.
 The equals method that returns true if two books have the same title and the same number of pages.
 The compareTo method that compares two books and returns -1 if the first book has less pages than the second one, 1 if the first book has more pages than the second one, and 0 if both books have same number of pages.

Answer 1

Source code of the program and its working are given below.Comments are also given along with the code for better understanding.Screen shot of the code and output are also attached.If find any difficulty, feel free to ask in comment section. Please do upvote the answer.Thank you.

Working of the program

• In Book class two instance variables pages and titles are declared
• A parametrized constructor is used to initialize variables
• getter and setter methods are defined to get and set values
• toString() method of Object class is overridden to print object information directly
• equals() method of Object class is overriden to check objects are equal or not
• compareTo() method is defined to compare pages of two books
• Inside Main class, Book objects are created and their information are printed
• By caling equals() method, objects are checked equal or not
• By calling compareTo() method,objects pages are compared.

Source code

Book class

//Book class definition
public class Book {
    //instance variable declaration
    private int pages;
    String title;
    //Constructor to initialize instance variables
    public Book(int pages, String title) {
        this.pages = pages;
        this.title = title;
    }
    //getter method for getting values
    public int getPages() {
        return pages;
    }

    public String getTitle() {
        return title;
    }
    //setter method for setting values
    public void setPages(int pages) {
        this.pages = pages;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    //overriding toString() method to print object information directly
    @Override
    public String toString() {
        return "\nBook title: "+title+"\nNumber of pages: "+pages;
    }

    //overriding equals() to check objects are equal or not
    @Override
    public boolean equals(Object obj) {
        //if the object compared with itself
       if(obj==this)
       {
           return true;
       }
       //if object is not the instance of Book
       if(!(obj instanceof Book))
       {
           return false;
       }
       //typecast obj to Book for comparing their data members
       Book b=(Book)obj;
       //compare the data members
       return Integer.compare(pages,((Book) obj).pages)==0 &&title.equals(((Book) obj).title);
    }
    //compareTo() method is used to compare pages
    public int compareTo(Book ob)
    {
        //if first book's pages less than second one's
        if(pages<ob.pages)
            return -1;
        //if first book's pages greater than second one's
        else if(pages>ob.pages)
            return 1;
        //if pages of both are equal
        else
            return 0;

    }
}

Main class

public class Main {
    public static void main(String[] args) {
        //creating Book objects
        Book b1 = new Book(200, "Learning Java");
        Book b2 = new Book(150, "python Introduction");
        Book b3 = new Book(200, "Learning Java");
        //printing their information
        System.out.println("Book information: ");
        System.out.println(b1);
        System.out.println(b2);
        System.out.println(b3);
        System.out.println();
        //checking objects are equal or not
        System.out.println(b1.equals(b2));
        System.out.println(b1.equals(b3));
        //comparing pages of two books
        System.out.println(b1.compareTo(b2));
    }
}

Screen shot of the code

Screen shot of the code